Further study of the global minimum constraint on the two-Higgs-doublet models: LHC searches for heavy Higgs bosons

TL;DR

This paper investigates the global minimum constraint in the two-Higgs-doublet model, analyzing its impact on the scalar potential parameters and the implications for heavy Higgs boson searches at the LHC.

Contribution

It introduces the GM constraint in the 2HDM, constrains the parameter space, and discusses its effects on heavy Higgs boson phenomenology at the LHC.

Findings

GM constraint limits the soft breaking parameter $m_{12}^2$.

Heavy Higgs masses are pushed to higher values for $m_{12}^2< 0$.

Implications for LHC heavy Higgs searches are discussed.

Abstract

The usually considered vacuum of the two-Higgs-doublet model (2HDM) could be unstable if it locates at a local but not global minimum (GM) of the scalar potential. By requiring the vacuum to be a GM, we obtain an additional constraint, namely the GM constraint, on the scalar potential. In this work, we explore the GM constraint on the $CP$-conserving general 2HDM. This constraint is found to put limits on the soft $\mathbb{Z}_2$ breaking mass parameter $m_{12}^2$ and also squeeze the heavy $CP$-even Higgs boson mass into larger values for the $m_{12}^2< 0$ case. Combined with the current global signal fits from the LHC measurements of the 125 GeV Higgs boson, we discuss the phenomenological implications for the heavy Higgs boson searches at the LHC.